Land mine, more particularly anti-tank mine



July 23, 1963 F. BERGER LAND MINE. MORE PARTICULARLY ANTI-TANK MINE 2 Sheets-Sheet 1 Filed June 2. 1960 Inventor: F L Zz B 21-9 m rpf/wz, m ,4 tr

July 23, 1963 F. BERGER 3,998,439

LAND MINE, MORE PARTICULARLY ANTI-TANK MINE Filed June 2, 1960 2 Sheets-Sheet 2 Fly. 2

Inventor":

Fritz B er-yer 3,ii8,43-9 Patented July 23, 1963 3,098,439 LAND MINE, MORE PARTKCULARLY ANTI-TANK MENE Fritz Berger, Dusseidort', Germany, assigner to Firma Rheinmetall G.m.h.l-l., Dusseidorf, Germany Filed June 2, 19m, Ser. No. 33,533 Claims priority, appiication Germany Jane 4, 1959 1 Ciaim. (Cl. lii2-8) The present invention relates to a land mine, more particularly an anti-tank mine, comprising an inner and an outer part which are guided to be capable of relative movement and in which the spring loaded striker of the fuze mechanism is actuated by the movement of the inner part relative to the outer part.

In known land mines the striker is in general provided with a striker spring which on being released causes the striker to be propelled forward, so that the firing pin is caused to impinge upon the firing cap with sufficient speed thereby causing the mechanism to fire the mine. Hitherto this striker spring was assembled with pre-compression in the fuze mechanism of the mine and was maintained in this pre-compressed position by complicated locking devices until the fuze mechanism was actuated when a person or a vehicle passed over the mine, thereby releasing the striker which would set off the mine.

However, such mines, which incorporated a striker pin which was assembled in the fuze in a state of compression, cannot be considered to be absolutely safe under all circumstances, since in their case there is a risk that the locking devices of a striker spring can be released accidentally e.g. due to shocks during transport or that they fail due to faulty material, resulting in premature firing and detonation of the mine. In addition, the striker spring, which is constantly subject to a compressive force, tends to creep, particularly after prolonged periods of storage, which may impair the efliciency of the fuze mechanism.

It is an object of the present invention to provide a mine, more particularly an anti-tank mine, in which the above mentioned disadvantages are overcome and which combines simple design on the one hand with reliable ignition and a high degree of safety against inadvertent actuation of the striker on the other hand.

To solve this problem according to the invention, the striker spring is located without compression in the fuze mechanism-which is provided with a shear plate serving as a safety device-between the inner and the outer part of the mine; the said spring being compressed by the movement of the inner part of the mine relative to the outer part and is released by the actuating mechanism after a predetermined relative movement has been exceeded.

Due to the fact that the proposed striker spring is incorporated into the mine without compression, the fuze is not acted upon by any force 'until it is loaded by a vehicle passing across the mine, so that the striker cannot be propelled forward, ie the mine cannot be set off prematurely, even though it may be subjected to vibrations of some magnitude. At the same time the shearing plate fitted to the fuze mechanism secures the striker spring against accidental compression; and by contrast this compression can only be applied to the spring after the shearing plate has been broken off e.g. by the vehicle passing over the mine. It is therefore possible to transport the new mine while the fuze is in position but without any additional safety pins which may have to be removed when the mine is laid, such transport being possible without any danger whatsoever.

Further details and advantages of the invention will now be explained by reference to an embodiment illustrated in the accompanying drawing in which FIG. 1 shows a land mine in longitudinal section incorporating the proposed fuze mechanism,

FIG. 2 shows the compression and release mechanism for the striker spring on an enlarged scale in longitudinal section,

FIG. 3 is a side elevation of the compression and release mechanism partly in section according to FIG. 2, and

FIG. 4 is a cross section taken on the line IV IV of FIG. 2 in the direction of the arrows through the compression and release mechanism.

Referring to the drawing, the disc shaped anti-tank mine illustrated consists of an inner part 1 slidable within an outer part 2 guided so as to be capable of relative movement. At the inner surface of the outer part 2 a retaining ring 3 is provided which partly extends laterally over the top part ll. Both the inner part 1 and the outer part 2,, as well as the retaining ring 3, consist preferably of a compressed weather-resistant high explosive charge, e.g., of a thermoplastic explosive such as Holtex so-called, so that no separate container for the mine need be furnished. The mine is sealed on the outside by means of a sealing ring 4. Inside the mine, between the inner part \1 and the outer part 2, a closed air pipe 5 of a flexible material, for example of rubber, is provided forming an elastic cushion between the inner and the outer parts. The flexible pipe element 5 is provided with a pressure relief valve 6 so that the air can escape therefrom when a vehicle passes across the mine, thereby allowing the inner part to move downward. In addition the outer part of the mine is furnished with a carrying handle (not shown on the drawing) made of a flexible plastic.

The movable inner part 1 is provided with a hole in the middle into which is inserted the fuze mechanism of the mine which as a whole is denoted 7. This fuze mech \anism consists essentially of the fuze body 8, a clamping bushing 9 incorporating the striker 10, striker spring 11 and a safety sleeve 12 locking the striker. In the em bodiment as drawn the firing cap 13 is located in the striker it while the safety sleeve 12 provides a mounting for the firing pin 14. The detonator 15 is located at the lower end of the clamping bushing 9. The fuze 7 together with the detonator vi5 is screwed into the inner part of the mine by means of the thread 16. When it is screwed in, a rubber ring .17 located between the fuze casing 8 and the top part 1 protects the inside of the mine against the entry of moisture.

According to the invention, the striker spring '11 is assembled into the fuze mechanism without pre-compression. It is only the movement of the inner part relative to the outer part which compresses this spring. T 0 prevent premature compression of the striker spring, a shearing plate .18 is provided as a safety device.

Since the striker 10 and the striker spring 11 are located inside the clamping bushing 9whioh can be forced into the fuze casing 8 by the movement of Ithe inner part of the mine relative to the outer partand since the striker spring is supported on one end by the clamping bushing, which is supported in turn by one part of the mine, and on the other end by the striker 10 and by the safety sleeve 12 locking the striker, which are supported in turn by the other part of the mine, every movement of the inner part of the mine, after the shearing plate 18 has been broken off, is transmitted with certainty to the striker spring by structurally particularly simple and reliable means. The shearing plate safety device is preferably located between the clamping bushing 9 and the fuze casing 8 in the fuze mechanism.

The safety sleeve 12 is supported by arms 19 with inwardly turned hooks 20 which in turn rest on the striker 10. The clamping bushing 9 is provided with corresponding slots 21 so that it is not obstructed by these hooks or arms when it is being forced into the fuze casing. On the outside these slots 21 are furnished with a step 22 which guides the arms 19 which are wider than the books 20. These steps are placed at an angle, forming a path 23 along which the arms 19 can slide. This causes the arms 19 to be splayed out, thereby increasingly compressing the striker spring 11. After this compression proc esswhich is accurately defined by the inclination and position of the oblique :surfaceshas been completed, i.e. after a pre-determined travel of the arms 19 and their hooks 20, the arms 19 are splayed out far enough to allow the hooks 20 to release the compressed striker spring in order to set oif the mine. Thus, the oblique surfaces 23 of the clamping bush, in conjunction with the arms 19 of the safety sleeve, form a simple and reliable actuating mechanism. To provide adequate elasticity for the arms 19, the safety sleeve and the arms are preferably made of an elastic plastic.

It is useful if all other components of the fuze including the sleeves for the firing cap 13 and the detonator 15 and the firing pin 14 are also made of a plastic which is suitable for the particular purpose of the mine. Apart from the reduction of weight this has the further advantage that the mines cannot be found by detectors. In the place of plastic, a rubber spring can also be used as the striker spring.

The method of operation of the proposed mine is as follows:

If a heavy vehicle, for example a tank, passes across the mine, the air cushion inside the flexible pipe element is first compressed by the inner part 1 of the mine, which carries the applied load. As the load increases, until the pressure relief valve 6 in the flexible pipe element begins to operate, the inner part 1 first moves downward until the end face 24 of the clamping bushing 9 comes in contact with the supporting surface 25 of the outer part of the mine. If the load on the mine is sufficiently great to break oh the shear plate 18, the striker spring-which is supported at one end by the clamping bush, and at the other end by the striker and hence by the hooks 20 of the safety sleeve-is compressed by the movement of the clamping bushing 9 relative to the fuze casing 8 which now commences. At the same time the arms 19 of the safety sleeve slide along the oblique faces 23 and are spread out far enough such that when the compression operation is completed the striker 10, which until then had been retained in position by the hooks 20, is released so that it is propelled, together with its firing cap 13, against the firing pin 14. This causes the firing cap 13 to be ignited, and the ignition is transmitted to the detonator 15. The latter finally detonates the explosive charge 1, 2 and 3 of the mine.

The proposed invention is not restricted to anti-tank mines. By suitable modification of the shear plate the mine can be used with equal effectiveness also against light vehicles or against persons.

What I claim is:

A detonator for a land mine particulanly for anti-tank mines, comprising two parts of which one is an inner and the other an outer part and both parts being relatively movable one within the other, a fuze body in the inner part comprising a safety sleeve having integral depending arms each with an inwardly projecting claw, a firing pin secured in the sleeve, a clamping bushing having slots therein one for each arm and cam surfaces adjacent each slot, a striker in the clamping bushing and provided with a firing cap, a spring in the bushing and contacting against the striker without tension in its normal position, said clamping bushing when movable relative to the fuze body compressing the spring and the arms contacting the cam surfaces to force the firing pin into the firing cap after a predetermined relative movement of the two parts has been exceeded with the claws releasing the safety sleeve, the claws of the depending arms being directed at right angles to the axis of the detonator whereby in the position of rest of the mine the claws will contact against the striker, the safety sleeve and its arms, the striker, the clamping bushing and the spring being composed of a plastic material, and a shear plate on the clamping bushing and cooperating with the fuze body so that when the shear plate is broken off by the clamping bushing striking the outer part it will be movable into the fuze body to cause a compression of the spring and ignition of the firing cap.

References Cited in the file of this patent UNITED STATES PATENTS 2,168,482 Junghans Aug. 8, 1939 2,358,403 Gore et al. Sept. 19, 1944 2,375,522 Campbell May 8, 1945 2,713,825 Liljegren July 26, 1955 FOREIGN PATENTS 202,890 Switzerland May 1, 1939 

